I just received a Tamarack TD3010 which is a clone of the original Hercules Graphics Card. I swapped it into my IBM XT taking out the original MDA card and hooked it up to my Princeton MAX-12 Monochrome TTL Phosphor monitor. When I turn on the IBM XT I am getting no video output. I tried running through the range of brightness, contrast, H and V sync on the monitor just to make sure something wasn't slightly out of spec but don't see any output regardless of monitor setup. There is a single jumper on the card which bridges the Vss and CS2 pins of the UM82C11 chip on the card. However the datasheet for that card shows it as being a printer port controller so I doubt that removing the jumper "JP2" would have any meaningful effect.

I was wondering if anyone had any potential troubleshooting tips for getting this card working. I've done a quick visual inspection for broken component legs, or obvious cold solder joints but nothing is popping out at me as being physically damaged. I suppose it could just be a case of a bad IC on the card in which case there is little to no chance of repairing it.